1/*
2 * Driver for Meywa-Denki & KAYAC YUREX
3 *
4 * Copyright (C) 2010 Tomoki Sekiyama (tomoki.sekiyama@gmail.com)
5 *
6 *	This program is free software; you can redistribute it and/or
7 *	modify it under the terms of the GNU General Public License as
8 *	published by the Free Software Foundation, version 2.
9 *
10 */
11
12#include <linux/kernel.h>
13#include <linux/errno.h>
14#include <linux/slab.h>
15#include <linux/module.h>
16#include <linux/kref.h>
17#include <linux/mutex.h>
18#include <linux/uaccess.h>
19#include <linux/usb.h>
20#include <linux/hid.h>
21
22#define DRIVER_AUTHOR "Tomoki Sekiyama"
23#define DRIVER_DESC "Driver for Meywa-Denki & KAYAC YUREX"
24
25#define YUREX_VENDOR_ID		0x0c45
26#define YUREX_PRODUCT_ID	0x1010
27
28#define CMD_ACK		'!'
29#define CMD_ANIMATE	'A'
30#define CMD_COUNT	'C'
31#define CMD_LED		'L'
32#define CMD_READ	'R'
33#define CMD_SET		'S'
34#define CMD_VERSION	'V'
35#define CMD_EOF		0x0d
36#define CMD_PADDING	0xff
37
38#define YUREX_BUF_SIZE		8
39#define YUREX_WRITE_TIMEOUT	(HZ*2)
40
41/* table of devices that work with this driver */
42static struct usb_device_id yurex_table[] = {
43	{ USB_DEVICE(YUREX_VENDOR_ID, YUREX_PRODUCT_ID) },
44	{ }					/* Terminating entry */
45};
46MODULE_DEVICE_TABLE(usb, yurex_table);
47
48#ifdef CONFIG_USB_DYNAMIC_MINORS
49#define YUREX_MINOR_BASE	0
50#else
51#define YUREX_MINOR_BASE	192
52#endif
53
54/* Structure to hold all of our device specific stuff */
55struct usb_yurex {
56	struct usb_device	*udev;
57	struct usb_interface	*interface;
58	__u8			int_in_endpointAddr;
59	struct urb		*urb;		/* URB for interrupt in */
60	unsigned char           *int_buffer;	/* buffer for intterupt in */
61	struct urb		*cntl_urb;	/* URB for control msg */
62	struct usb_ctrlrequest	*cntl_req;	/* req for control msg */
63	unsigned char		*cntl_buffer;	/* buffer for control msg */
64
65	struct kref		kref;
66	struct mutex		io_mutex;
67	struct fasync_struct	*async_queue;
68	wait_queue_head_t	waitq;
69
70	spinlock_t		lock;
71	__s64			bbu;		/* BBU from device */
72};
73#define to_yurex_dev(d) container_of(d, struct usb_yurex, kref)
74
75static struct usb_driver yurex_driver;
76static const struct file_operations yurex_fops;
77
78
79static void yurex_control_callback(struct urb *urb)
80{
81	struct usb_yurex *dev = urb->context;
82	int status = urb->status;
83
84	if (status) {
85		dev_err(&urb->dev->dev, "%s - control failed: %d\n",
86			__func__, status);
87		wake_up_interruptible(&dev->waitq);
88		return;
89	}
90	/* on success, sender woken up by CMD_ACK int in, or timeout */
91}
92
93static void yurex_delete(struct kref *kref)
94{
95	struct usb_yurex *dev = to_yurex_dev(kref);
96
97	dev_dbg(&dev->interface->dev, "%s\n", __func__);
98
99	usb_put_dev(dev->udev);
100	if (dev->cntl_urb) {
101		usb_kill_urb(dev->cntl_urb);
102		kfree(dev->cntl_req);
103		if (dev->cntl_buffer)
104			usb_free_coherent(dev->udev, YUREX_BUF_SIZE,
105				dev->cntl_buffer, dev->cntl_urb->transfer_dma);
106		usb_free_urb(dev->cntl_urb);
107	}
108	if (dev->urb) {
109		usb_kill_urb(dev->urb);
110		if (dev->int_buffer)
111			usb_free_coherent(dev->udev, YUREX_BUF_SIZE,
112				dev->int_buffer, dev->urb->transfer_dma);
113		usb_free_urb(dev->urb);
114	}
115	kfree(dev);
116}
117
118/*
119 * usb class driver info in order to get a minor number from the usb core,
120 * and to have the device registered with the driver core
121 */
122static struct usb_class_driver yurex_class = {
123	.name =		"yurex%d",
124	.fops =		&yurex_fops,
125	.minor_base =	YUREX_MINOR_BASE,
126};
127
128static void yurex_interrupt(struct urb *urb)
129{
130	struct usb_yurex *dev = urb->context;
131	unsigned char *buf = dev->int_buffer;
132	int status = urb->status;
133	unsigned long flags;
134	int retval, i;
135
136	switch (status) {
137	case 0: /*success*/
138		break;
139	case -EOVERFLOW:
140		dev_err(&dev->interface->dev,
141			"%s - overflow with length %d, actual length is %d\n",
142			__func__, YUREX_BUF_SIZE, dev->urb->actual_length);
143	case -ECONNRESET:
144	case -ENOENT:
145	case -ESHUTDOWN:
146	case -EILSEQ:
147		/* The device is terminated, clean up */
148		return;
149	default:
150		dev_err(&dev->interface->dev,
151			"%s - unknown status received: %d\n", __func__, status);
152		goto exit;
153	}
154
155	/* handle received message */
156	switch (buf[0]) {
157	case CMD_COUNT:
158	case CMD_READ:
159		if (buf[6] == CMD_EOF) {
160			spin_lock_irqsave(&dev->lock, flags);
161			dev->bbu = 0;
162			for (i = 1; i < 6; i++) {
163				dev->bbu += buf[i];
164				if (i != 5)
165					dev->bbu <<= 8;
166			}
167			dev_dbg(&dev->interface->dev, "%s count: %lld\n",
168				__func__, dev->bbu);
169			spin_unlock_irqrestore(&dev->lock, flags);
170
171			kill_fasync(&dev->async_queue, SIGIO, POLL_IN);
172		}
173		else
174			dev_dbg(&dev->interface->dev,
175				"data format error - no EOF\n");
176		break;
177	case CMD_ACK:
178		dev_dbg(&dev->interface->dev, "%s ack: %c\n",
179			__func__, buf[1]);
180		wake_up_interruptible(&dev->waitq);
181		break;
182	}
183
184exit:
185	retval = usb_submit_urb(dev->urb, GFP_ATOMIC);
186	if (retval) {
187		dev_err(&dev->interface->dev, "%s - usb_submit_urb failed: %d\n",
188			__func__, retval);
189	}
190}
191
192static int yurex_probe(struct usb_interface *interface, const struct usb_device_id *id)
193{
194	struct usb_yurex *dev;
195	struct usb_host_interface *iface_desc;
196	struct usb_endpoint_descriptor *endpoint;
197	int retval = -ENOMEM;
198	int i;
199	DEFINE_WAIT(wait);
200
201	/* allocate memory for our device state and initialize it */
202	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
203	if (!dev) {
204		dev_err(&interface->dev, "Out of memory\n");
205		goto error;
206	}
207	kref_init(&dev->kref);
208	mutex_init(&dev->io_mutex);
209	spin_lock_init(&dev->lock);
210	init_waitqueue_head(&dev->waitq);
211
212	dev->udev = usb_get_dev(interface_to_usbdev(interface));
213	dev->interface = interface;
214
215	/* set up the endpoint information */
216	iface_desc = interface->cur_altsetting;
217	for (i = 0; i < iface_desc->desc.bNumEndpoints; i++) {
218		endpoint = &iface_desc->endpoint[i].desc;
219
220		if (usb_endpoint_is_int_in(endpoint)) {
221			dev->int_in_endpointAddr = endpoint->bEndpointAddress;
222			break;
223		}
224	}
225	if (!dev->int_in_endpointAddr) {
226		retval = -ENODEV;
227		dev_err(&interface->dev, "Could not find endpoints\n");
228		goto error;
229	}
230
231
232	/* allocate control URB */
233	dev->cntl_urb = usb_alloc_urb(0, GFP_KERNEL);
234	if (!dev->cntl_urb) {
235		dev_err(&interface->dev, "Could not allocate control URB\n");
236		goto error;
237	}
238
239	/* allocate buffer for control req */
240	dev->cntl_req = kmalloc(YUREX_BUF_SIZE, GFP_KERNEL);
241	if (!dev->cntl_req) {
242		dev_err(&interface->dev, "Could not allocate cntl_req\n");
243		goto error;
244	}
245
246	/* allocate buffer for control msg */
247	dev->cntl_buffer = usb_alloc_coherent(dev->udev, YUREX_BUF_SIZE,
248					      GFP_KERNEL,
249					      &dev->cntl_urb->transfer_dma);
250	if (!dev->cntl_buffer) {
251		dev_err(&interface->dev, "Could not allocate cntl_buffer\n");
252		goto error;
253	}
254
255	/* configure control URB */
256	dev->cntl_req->bRequestType = USB_DIR_OUT | USB_TYPE_CLASS |
257				      USB_RECIP_INTERFACE;
258	dev->cntl_req->bRequest	= HID_REQ_SET_REPORT;
259	dev->cntl_req->wValue	= cpu_to_le16((HID_OUTPUT_REPORT + 1) << 8);
260	dev->cntl_req->wIndex	= cpu_to_le16(iface_desc->desc.bInterfaceNumber);
261	dev->cntl_req->wLength	= cpu_to_le16(YUREX_BUF_SIZE);
262
263	usb_fill_control_urb(dev->cntl_urb, dev->udev,
264			     usb_sndctrlpipe(dev->udev, 0),
265			     (void *)dev->cntl_req, dev->cntl_buffer,
266			     YUREX_BUF_SIZE, yurex_control_callback, dev);
267	dev->cntl_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
268
269
270	/* allocate interrupt URB */
271	dev->urb = usb_alloc_urb(0, GFP_KERNEL);
272	if (!dev->urb) {
273		dev_err(&interface->dev, "Could not allocate URB\n");
274		goto error;
275	}
276
277	/* allocate buffer for interrupt in */
278	dev->int_buffer = usb_alloc_coherent(dev->udev, YUREX_BUF_SIZE,
279					GFP_KERNEL, &dev->urb->transfer_dma);
280	if (!dev->int_buffer) {
281		dev_err(&interface->dev, "Could not allocate int_buffer\n");
282		goto error;
283	}
284
285	/* configure interrupt URB */
286	usb_fill_int_urb(dev->urb, dev->udev,
287			 usb_rcvintpipe(dev->udev, dev->int_in_endpointAddr),
288			 dev->int_buffer, YUREX_BUF_SIZE, yurex_interrupt,
289			 dev, 1);
290	dev->urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
291	if (usb_submit_urb(dev->urb, GFP_KERNEL)) {
292		retval = -EIO;
293		dev_err(&interface->dev, "Could not submitting URB\n");
294		goto error;
295	}
296
297	/* save our data pointer in this interface device */
298	usb_set_intfdata(interface, dev);
299	dev->bbu = -1;
300
301	/* we can register the device now, as it is ready */
302	retval = usb_register_dev(interface, &yurex_class);
303	if (retval) {
304		dev_err(&interface->dev,
305			"Not able to get a minor for this device.\n");
306		usb_set_intfdata(interface, NULL);
307		goto error;
308	}
309
310	dev_info(&interface->dev,
311		 "USB YUREX device now attached to Yurex #%d\n",
312		 interface->minor);
313
314	return 0;
315
316error:
317	if (dev)
318		/* this frees allocated memory */
319		kref_put(&dev->kref, yurex_delete);
320	return retval;
321}
322
323static void yurex_disconnect(struct usb_interface *interface)
324{
325	struct usb_yurex *dev;
326	int minor = interface->minor;
327
328	dev = usb_get_intfdata(interface);
329	usb_set_intfdata(interface, NULL);
330
331	/* give back our minor */
332	usb_deregister_dev(interface, &yurex_class);
333
334	/* prevent more I/O from starting */
335	mutex_lock(&dev->io_mutex);
336	dev->interface = NULL;
337	mutex_unlock(&dev->io_mutex);
338
339	/* wakeup waiters */
340	kill_fasync(&dev->async_queue, SIGIO, POLL_IN);
341	wake_up_interruptible(&dev->waitq);
342
343	/* decrement our usage count */
344	kref_put(&dev->kref, yurex_delete);
345
346	dev_info(&interface->dev, "USB YUREX #%d now disconnected\n", minor);
347}
348
349static struct usb_driver yurex_driver = {
350	.name =		"yurex",
351	.probe =	yurex_probe,
352	.disconnect =	yurex_disconnect,
353	.id_table =	yurex_table,
354};
355
356
357static int yurex_fasync(int fd, struct file *file, int on)
358{
359	struct usb_yurex *dev;
360
361	dev = file->private_data;
362	return fasync_helper(fd, file, on, &dev->async_queue);
363}
364
365static int yurex_open(struct inode *inode, struct file *file)
366{
367	struct usb_yurex *dev;
368	struct usb_interface *interface;
369	int subminor;
370	int retval = 0;
371
372	subminor = iminor(inode);
373
374	interface = usb_find_interface(&yurex_driver, subminor);
375	if (!interface) {
376		printk(KERN_ERR "%s - error, can't find device for minor %d",
377		       __func__, subminor);
378		retval = -ENODEV;
379		goto exit;
380	}
381
382	dev = usb_get_intfdata(interface);
383	if (!dev) {
384		retval = -ENODEV;
385		goto exit;
386	}
387
388	/* increment our usage count for the device */
389	kref_get(&dev->kref);
390
391	/* save our object in the file's private structure */
392	mutex_lock(&dev->io_mutex);
393	file->private_data = dev;
394	mutex_unlock(&dev->io_mutex);
395
396exit:
397	return retval;
398}
399
400static int yurex_release(struct inode *inode, struct file *file)
401{
402	struct usb_yurex *dev;
403
404	dev = file->private_data;
405	if (dev == NULL)
406		return -ENODEV;
407
408	/* decrement the count on our device */
409	kref_put(&dev->kref, yurex_delete);
410	return 0;
411}
412
413static ssize_t yurex_read(struct file *file, char __user *buffer, size_t count,
414			  loff_t *ppos)
415{
416	struct usb_yurex *dev;
417	int retval = 0;
418	int bytes_read = 0;
419	char in_buffer[20];
420	unsigned long flags;
421
422	dev = file->private_data;
423
424	mutex_lock(&dev->io_mutex);
425	if (!dev->interface) {		/* already disconnected */
426		retval = -ENODEV;
427		goto exit;
428	}
429
430	spin_lock_irqsave(&dev->lock, flags);
431	bytes_read = snprintf(in_buffer, 20, "%lld\n", dev->bbu);
432	spin_unlock_irqrestore(&dev->lock, flags);
433
434	if (*ppos < bytes_read) {
435		if (copy_to_user(buffer, in_buffer + *ppos, bytes_read - *ppos))
436			retval = -EFAULT;
437		else {
438			retval = bytes_read - *ppos;
439			*ppos += bytes_read;
440		}
441	}
442
443exit:
444	mutex_unlock(&dev->io_mutex);
445	return retval;
446}
447
448static ssize_t yurex_write(struct file *file, const char __user *user_buffer,
449			   size_t count, loff_t *ppos)
450{
451	struct usb_yurex *dev;
452	int i, set = 0, retval = 0;
453	char buffer[16];
454	char *data = buffer;
455	unsigned long long c, c2 = 0;
456	signed long timeout = 0;
457	DEFINE_WAIT(wait);
458
459	count = min(sizeof(buffer), count);
460	dev = file->private_data;
461
462	/* verify that we actually have some data to write */
463	if (count == 0)
464		goto error;
465
466	mutex_lock(&dev->io_mutex);
467	if (!dev->interface) {		/* already disconnected */
468		mutex_unlock(&dev->io_mutex);
469		retval = -ENODEV;
470		goto error;
471	}
472
473	if (copy_from_user(buffer, user_buffer, count)) {
474		mutex_unlock(&dev->io_mutex);
475		retval = -EFAULT;
476		goto error;
477	}
478	memset(dev->cntl_buffer, CMD_PADDING, YUREX_BUF_SIZE);
479
480	switch (buffer[0]) {
481	case CMD_ANIMATE:
482	case CMD_LED:
483		dev->cntl_buffer[0] = buffer[0];
484		dev->cntl_buffer[1] = buffer[1];
485		dev->cntl_buffer[2] = CMD_EOF;
486		break;
487	case CMD_READ:
488	case CMD_VERSION:
489		dev->cntl_buffer[0] = buffer[0];
490		dev->cntl_buffer[1] = 0x00;
491		dev->cntl_buffer[2] = CMD_EOF;
492		break;
493	case CMD_SET:
494		data++;
495		/* FALL THROUGH */
496	case '0' ... '9':
497		set = 1;
498		c = c2 = simple_strtoull(data, NULL, 0);
499		dev->cntl_buffer[0] = CMD_SET;
500		for (i = 1; i < 6; i++) {
501			dev->cntl_buffer[i] = (c>>32) & 0xff;
502			c <<= 8;
503		}
504		buffer[6] = CMD_EOF;
505		break;
506	default:
507		mutex_unlock(&dev->io_mutex);
508		return -EINVAL;
509	}
510
511	/* send the data as the control msg */
512	prepare_to_wait(&dev->waitq, &wait, TASK_INTERRUPTIBLE);
513	dev_dbg(&dev->interface->dev, "%s - submit %c\n", __func__,
514		dev->cntl_buffer[0]);
515	retval = usb_submit_urb(dev->cntl_urb, GFP_KERNEL);
516	if (retval >= 0)
517		timeout = schedule_timeout(YUREX_WRITE_TIMEOUT);
518	finish_wait(&dev->waitq, &wait);
519
520	mutex_unlock(&dev->io_mutex);
521
522	if (retval < 0) {
523		dev_err(&dev->interface->dev,
524			"%s - failed to send bulk msg, error %d\n",
525			__func__, retval);
526		goto error;
527	}
528	if (set && timeout)
529		dev->bbu = c2;
530	return timeout ? count : -EIO;
531
532error:
533	return retval;
534}
535
536static const struct file_operations yurex_fops = {
537	.owner =	THIS_MODULE,
538	.read =		yurex_read,
539	.write =	yurex_write,
540	.open =		yurex_open,
541	.release =	yurex_release,
542	.fasync	=	yurex_fasync,
543	.llseek =	default_llseek,
544};
545
546module_usb_driver(yurex_driver);
547
548MODULE_LICENSE("GPL");
549